Salvage therapy for patients who have failed Nelfinavir therapy as defined as RNA>1000 copies after 16 weeks of treatment. The purpose of this study is to see how many people will have an undetectable amount of HIV in the blood(less than 200 copies/ml) after 8 and 24 weeks of treatment and see how long this lasts over time. Also we wish to see if these drugs are safe to take in combination and how well they are tolerated. The study will use the following anti-HIV drugs that are FDA -approved: saquinavir(SQV), indinavir(IDV), ritonavir(RTV), zidovudine(ZDV), lamivudine(3TC), stavudine(d4T) and didanosine(ddI). In addition, the study will use amprenavir(APV) and efavirenz(EFV) which are investigational anti-HIV drugs(not approved by the FDA). Both these investigational drugs have been tested in a small number of volunteers and have shown they may be helpful in preventing the HIV virus from multiplying in the body.